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icult to know what is 〃natural〃 and what is cultural。 In the widest sense everything is natural； in the narrowest very few things are natural。 Cooked food； clothing； houses； marriages； education； etc。； are not found in a state of nature； any more than clocks and plays by Ibsen are。 Our judgment as to what is good and bad is mainly instinctive leaning directed or smothered by education。
The stimuli that thus pour in upon the individual； and to which he must react； must find an organism ready to respond in some way or other。 A sleeping man naturally does not adjust himself to danger； nor does a paralyzed man fly。 The most attractive female in the world causes no response in the very young male child and perhaps stirs only reminiscences in the aged。 Food； which causes the saliva to flow in the mouth of the hungry； may disgust the full。 Throughout life there are factors in the internal life of the organism instantly changing one's reaction to things of physical； mental and moral significance。 He talks loudest of restraint and control who has no desire； and in satiation even the sinner sees the beauty of asceticism。 There must be a coincidence of stimulus； readiness and opportunity for the full； successful response to take place。＇1＇ ＇1＇ A slang epigram puts it better： The time； the place； and the girl。
The simplest response to any stimulus from the outer world is the reflex act。 Theoretically a reflex act is dependent upon the interaction of a sensory surface； a sensory nerve cell； a motor nerve cell and a muscle； i。 e。； a receptive apparatus and a motor apparatus in such close union that the will and intelligence play no part。 Thus if one puts his finger on a hot stove he withdraws it immediately； and such responses are present even in the decapitated frog and human for a short time。 So if light streams in on the wide…open pupil of the eye； it contracts； grows smaller； without any effort of the will； and in fact entirely without the consciousness of the individual。 Swallowing is a series of reflexes in a row； so that food in the back part of the mouth sets a reflex going that carries it beyond the epiglottis； another reflex carries it to the esophagus and then one reflex after the other transports the food the rest of the way。 Except for the first effort of swallowing； the rest is entirely involuntary and even unconscious。 Those readers who are interested would do well to read the work of Pavlow on the conditioned reflex； in which the great Russian physiologist builds up all action on a basis of a modification of the primitive reflex which he calls the 〃conditioned reflex。〃＇1＇ ＇1＇ Pavlow is one of the scientists who regard all mental life as built up out of reflexes。 The immediate reflex is only one variety； thought； emotion； etc。； are merely reflexes placed end to end。 Pavlow divides action into two trends； one due to an unconditioned reflex； of innate structure； and the other a modified or conditioned reflex which arises because some stimulus has become associated with the reflex act。 Thus saliva dripping from a dog's mouth at the smell of food is an unconditioned reflex； if a bell is heard at the same time the food is smelled then in the course of time the saliva flows at the sound of the bell alone；a conditioned reflex。 A very complex system has been built up of this kind of facts； which I have criticized elsewhere。
The simple reflex； immediate response to a stimulus； has only a limited field in human life or adult life。 Sherrington points out in his notable book； 〃The Integrative Action of the Nervous System；〃 that there is a play of the entire organism on each responding element； and there is also a competition throughout each pathway to action。 Let us examine this a little closer。 A man is hungry； let us say； i。 e。； there arise from his gastro…intestinal tract and from the tissues stimuli which arouse motor mechanisms to action and the man seeks food。 The need of the body arouses desire in the form of an organic sensation and this arouses mechanisms whose function is to satisfy that desire。 Let us assume that he finds something that looks good and he is about to seize it when an odor； called disagreeable； assails his nostrils from the food； which stops him。 Then there arises a competition for action between the desire for food and the visual stimulus； associated memories； etc。； on the one hand； and the odor； the awakened fear； memories； disgust； etc。； on the other hand。 This struggle for action； for use of the mechanisms of action； is the struggling of choosing； one of the fundamental phenomena of life。 In order for a choice to become manifest； what is known as inhibition must come into play； an impulse to action must be checked in order that an opposing action can be effective。 The movement of rejection uses muscles that oppose the movement of acquirement； e。 g。； one uses the triceps and the other the biceps； muscles situated in opposite sides of the upper arm and having antagonistic action。 In order for triceps to act； biceps must be inhibited from action； and in that inhibition is a fundamental function of the organism。 In every function of the body there are opposing groups of forces； for every dilator there is a contractor； for every accelerator of action there is inhibition。 Nature drives by two reins； and one is a checkrein。 This function of inhibition； then； delays； retards or prevents an action and is in one sense a higher function than the response to stimulation。 Its main seat is the cerebrum； the 〃highest〃 nervous tissue； whereas reflex and instinctive actions usually are in the vegetative nervous system； the spinal cord； the bulbar regions and the mid…brain； all of which are lower centers。 Choice； which is intimately associated with inhibition； is par excellence a cerebral function and in general is associated with intense consciousness。 The act of choosing brings to the circumstances the whole past history of the individual； it marshals his resources of judgment； intelligence； will； purposes and desires。 In choice lies the fate of the personality； for it is basically related to habit formation。 Further； in the dynamics of life a right； proper choice； an appropriate choice； opens wide the door of opportunity； whereas an unfortunate choice may commit one to the mercies of wrecking forces。 Education should aim to teach proper choosing and then proper action。 The capacity for perceiving and responding to stimuli； for inhibiting or delaying action and for choosing； are of cardinal importance in our study。 But there is another phase of life and character without which everything else lacks unity and is unintelligible。 From the beginning of life to the end there is choice。 Who and what chooses？ From infancy one sees the war of purposes and desires and the gradual rise of one purpose or set of purposes into dominance；in short； the growth of unity； the growth of personality。 The common man calls this unity his soul； the philosopher speaks of the ego and implies some such thing as this organizing energy of character。 But a naturalistic view of character must reject such a metaphysical entity； for one sees the organizing energy increase and diminish with the rest of character through health； age； environment； etc。 Further； there is at work in all living things a similar something that organizes the action of the humblest bit of protoplasm。 This organizing energy of character will be； for us； that something inherent in all life which tends to individualize each living thing。 It is as if all life were originally of one piece and then； spreading itself throughout the world； it tended to differentiate and develop （according to the Spencerian formula） into genera； species； groups and individuals。 This organizing energy works up the experiences of the individual so that new formulae for action develop； so that what is experienced becomes the basis of future reaction。 It must be remembered that the world we live in has its great habits。 Night follows day in a cycle that never fails； the seasons are repeated each year； and there is a periodicity in the lives of plants and animals that is manifested in growth； nutrition； mating and resting。 Things happen again and again； though in slightly altered form； and our desires； satisfie